Since returning to office in 2025, Donald Trump's administration has deported more than 25,000 migrants, refugees and asylum seekers to countries that are not their own.

Human rights lawyers describe these so-called third-country national arrangements as a "show of force", intended to make people fear the consequences of entering the US without permission.

To compile the most comprehensive account of a policy that has mostly operated behind closed doors, the Guardian joined 23 other media organisations in the Deportation Project, a joint investigation coordinated by Paris-based Forbidden Stories. The consortium interviewed more than 100 people affected by, or involved in, the US drive to extinguish unauthorised immigration, and reviewed documents outlining details of the agreements made by US officials with governments around the world.